EHN: improve plot () 3D

solve bug
BUG: debug some probs with 3D

update and axis
Merge branch 'ENH_background_for_plot' into NEW_edsSpectrum

Conflicts:
	hyperspy/signal.py
EHN: quant()

Implement quant() from the the kratios using an external software, Stratagem.
Unfortunnately this sofware is commercial and requires a licence.